IEC60255–121: The new standard for type-testing distance relays: Are the proposed tests feasible and is it worth the effort?

The paper presents a brief overview of the standard IEC60255–121 and focusses on the challenges and advantages of using transient simulation for assessing protective relays. The importance of the use of statistical methods to investigate the behaviour of algorithms is discussed. Finally a new solution for performing these kinds of tests is introduced.